Have you read thru the adventures of COZX2 on gassavers? He did a loooot of EOC and ended up with a half blocked radiator for winter driving. Of course he had a steady commute, which it seems you don't have. In fact he stuffed his entire engine compartment with R30 bat's to help keep the heat in because EOC'ing he couldn't keep his temps up. I believe he would run the car up to temp and then start the EOC and if the temps got out of hand, he'd just turn on his rad fan (on a manual switch). He also had a block heater
I really like mine.